Some environment variables are necessary for native language support. Setting them properly results in:
The output of programs being translated into your native language
The correct classification of characters into letters, digits and other classes. This is necessary for bash to properly accept non-ASCII characters in command lines in non-English locales
The correct alphabetical sorting order for the country
The appropriate default paper size
The correct formatting of monetary, time, and date values
Replace <ll>
below
with the two-letter code for your desired language (e.g.,
en
) and <CC>
with the two-letter code
for the appropriate country (e.g., GB
).
<charmap>
should be
replaced with the canonical charmap for your chosen locale. Optional
modifiers such as @euro
may also be
present.
The list of all locales supported by Glibc can be obtained by running the following command:
locale -a
Charmaps can have a number of aliases, e.g., ISO-8859-1
is also referred to as iso8859-1
and iso88591
.
Some applications cannot handle the various synonyms correctly (e.g.,
require that UTF-8
is written as
UTF-8
, not utf8
), so it is the safest in most cases to choose
the canonical name for a particular locale. To determine the
canonical name, run the following command, where <locale name>
is the output
given by locale -a for
your preferred locale (en_GB.iso88591
in
our example).
LC_ALL=<locale name>
locale charmap
For the en_GB.iso88591
locale, the above
command will print:
ISO-8859-1
This results in a final locale setting of en_GB.ISO-8859-1
. It is important that the locale
found using the heuristic above is tested prior to it being added to
the Bash startup files:
LC_ALL=<locale name> locale language LC_ALL=<locale name> locale charmap LC_ALL=<locale name> locale int_curr_symbol LC_ALL=<locale name> locale int_prefix
The above commands should print the language name, the character encoding used by the locale, the local currency, and the prefix to dial before the telephone number in order to get into the country. If any of the commands above fail with a message similar to the one shown below, this means that your locale was either not installed in Chapter 8 or is not supported by the default installation of Glibc.
locale: Cannot set LC_* to default locale: No such file or directory
If this happens, you should either install the desired locale using the localedef command, or consider choosing a different locale. Further instructions assume that there are no such error messages from Glibc.
Other packages can also function incorrectly (but may not necessarily display any error messages) if the locale name does not meet their expectations. In those cases, investigating how other Linux distributions support your locale might provide some useful information.
Once the proper locale settings have been determined, create the
/etc/locale.conf
file:
cat > /etc/locale.conf << "EOF"
LANG=<ll>_<CC>.<charmap><@modifiers>
EOF
The shell program /bin/bash (here after referred as
“the shell”)
uses a collection of startup files to help create the environment to
run in. Each file has a specific use and may affect login and
interactive environments differently. The files in the /etc
directory provide global settings. If
equivalent files exist in the home directory, they may override the
global settings.
An interactive login shell is started after a successful login, using
/bin/login, by reading
the /etc/passwd
file. An interactive
non-login shell is started at the command-line (e.g. [prompt]$
/bin/bash). A non-interactive shell
is usually present when a shell script is running. It is
non-interactive because it is processing a script and not waiting for
user input between commands.
The login shells are often unaffected by the
settings in /etc/locale.conf
.
Create the /etc/profile
to read the locale settings from /etc/locale.conf
and export them, but set
the C.UTF-8
locale instead if running in
the Linux console (to prevent programs from outputting characters
that the Linux console is unable to render):
cat > /etc/profile << "EOF"
# Begin /etc/profile
for i in $(locale); do
unset ${i%=*}
done
if [[ "$TERM" = linux ]]; then
export LANG=C.UTF-8
else
source /etc/locale.conf
for i in $(locale); do
key=${i%=*}
if [[ -v $key ]]; then
export $key
fi
done
fi
# End /etc/profile
EOF
Note that you can modify /etc/locale.conf
with the systemd localectl utility. To use
localectl for the
example above, run:
localectl set-locale LANG="<ll>_<CC>.<charmap><@modifiers>
"
You can also specify other language specific environment variables
such as LANG
, LC_CTYPE
, LC_NUMERIC
or any
other environment variable from locale output. Just separate them
with a space. An example where LANG
is set
as en_US.UTF-8 but LC_CTYPE
is set as just
en_US is:
localectl set-locale LANG="en_US.UTF-8" LC_CTYPE="en_US"
Please note that the localectl command doesn't work in the chroot environment. It can only be used after the LFS system is booted with systemd.
The C
(default) and en_US
(the recommended one for United States English
users) locales are different. C
uses the
US-ASCII 7-bit character set, and treats bytes with the high bit set
as invalid characters. That's why, e.g., the ls command substitutes them with
question marks in that locale. Also, an attempt to send mail with
such characters from Mutt or Pine results in non-RFC-conforming
messages being sent (the charset in the outgoing mail is indicated as
unknown 8-bit
). It's suggested
that you use the C
locale only if you
are certain that you will never need 8-bit characters.